On large industrial construction sites, e.g. chemical plants, refineries, oil and gas facilities, LNG facilities, the installation of a large number of flanges with multiple bolts is required. In order for the site to operate safely, the bolts are to be fastened by applying a sufficient amount of torque in a predetermined torqueing pattern. This is a time and money consuming process.
It is desired that a permanent record is stored, for instance for quality audit sessions. Therefore, the bolting process, executed by a worker, is often witnessed by an inspector to ensure that such a permanent record is developed in the form of a written record.
This further contributes to the time and costs, in particular since inspectors may not always be available, thereby delaying the bolting process.
U.S. Pat. No. 7,984,657 discloses a wireless-enabled tightening system for fasteners. The system includes a visual designator configured to project an indicator onto a work piece. The system also includes a torque wrench comprising a wireless transmitter and a means for identifying whether the correct torque has been applied to a fastener on the work piece and configured to provide a feedback for a user. The system also includes a camera configured to capture an image of the work piece when an appropriate amount of torque has been applied to the fastener. The system further includes a microprocessor for determining sequence of the fastener and identifying the tightened fastener.
The system of U.S. Pat. No. 7,984,657 requires a camera configured to capture an image of the work piece during the entire installing process and a visual designator, which are both not very practical on a large industrial construction sites. Also, U.S. Pat. No. 7,984,657 requires significant processing power necessary to compare image and significant network bandwidth to transmit image data files. Furthermore, the functioning of U.S. Pat. No. 7,984,657 relies on a “known environment”, which isn't always available.
Reference is further made to US2014/0336810A1, GB2514264A, CN204818666U, JP2015196231, WO201434194, WO201399373, JP2011240425, KR20110054491, WO201128362, US20110023280 and JP2000111450.